Aircraft safety is an ongoing concern for aircraft producers. An unknown loose object on board an aircraft may cause an aircraft to malfunction or not operate as designed thereby decreasing safety of the aircraft. In the art, unknown loose objects are referred to as foreign object debris (FOD). FOD is difficult to detect and many hours of searching for FOD occurs during the production of an aircraft, to assure the aircraft is free from loose objects, before the aircraft leaves a production facility or is operated. Moreover, because the detection of FOD can rely on visual inspection, it can be subject to human error. Furthermore, confined nature of an aircraft structure hinders vehicle through inspection.
FOD may be of various sizes and shapes and can go undetected in large aircraft. A large aircraft has various cavities, pockets, and crevices that cause the process of detecting FOD to be difficult. For example, a small FOD item, such as a rivet or nut, lying in a dark crevice may go undetected. The larger the amount of undetected FOD the increased likelihood of an aircraft system malfunctioning.
Thousands of rivets are typically used as fasteners on current aircraft. The rivets are attached or fastened via a rivet gun. A common example of a type of rivet that is often used is the blind rivet. Before installation the rivets are part of a rivet assembly. The rivet assembly includes a stem, a driving anvil or anvil washer, a holding ring and the rivet itself. During the installation of a rivet, a stem is inserted into a nose of a rivet gun. The shank of the rivet is inserted into a hole and pressure is applied on the head of the rivet. The stem is pulled out from the rivet causing a portion of the rivet that is extending through the object to increase in diameter. The head of the rivet and the expanded inserted portion lock the rivet in place.
The anvil washer holds the ring down tight on the rivet such that during and after installation of the rivet the ring does not loosen. When the ring is loose the rivet is not tightly fastened to the objects of interest and therefore must be removed and replaced. During installation of the rivet the stem is removed and caught by the rivet gun. However, often the anvil washer is not retained and can fall into the aircraft creating FOD. The anvil washers are typically small and difficult to find.
Thus, there exists a need for an improved technique for installation of rivets without the creation of FOD, thereby, reducing time and costs involved in manufacturing of an aircraft.